Mechanism of recombinant bacteria adsorb UO₂²⁺ under culture condition

Research on the ability and mechanism of genetically recombinant E. coli DH5α containing DSR A gene to enrich uranium under culture conditions provides a theoretical basis for the application of the bacteria in the treatment of uranium pollution. By exploring the influence of factors such as the initial concentration of uranium, culture time, and inoculation amount on the characteristics of uranium enrichment in genetically recombinant E. coli, using FTIR, SEM-EDS, XPS and XRD explore the mechanism of uranium-enriched bacteria. The results showed that when initial UO₂²⁺ concentration reach 600 mg/L, E. Coli D1 could not survived, indicated that the maximum tolerance concentration is lower than 600 mg/L. While concentration between 0∼500 mg/L, strains D1 can grow normally and has the ability to enrich uranium. In the prime stage, strains D1 resist toxics through release inorganic phosphates to precipitate UO₂²⁺ on cell wall, after 96 h, most UO₂²⁺ were transferred into cytoplasm and metabolized into U(IV) which is less toxic. In the metabolize process, all groups involved in metabolizing UO₂²⁺, especially protein contain groups like hydroxyl, amine and carboxyl paly a huge role. It shows that within a certain concentration rage, strains D1 has a good enrichment effect on uranium under culture conditions.